In many electrical, or electronic, musical instruments of today both hands of the musician are usually fully occupied in the creation of musical notes and in some instances the musician's foot is employed for obtaining, or control of, expression in the music. This is especially so in the case of the so-called keyboard instruments, and especially electronic organs, synthesizers and the like. The aim, for example, of an electronic organ is to closely simulate the sounds and timbre of many solo instruments which have totally different wave complexities, such as variable vibrato in the case of a violin and selective attack in the case of a piano. A form of synthesizer known as the "THEREMIN" has been proposed which utilizes a proximity detector device responsive to the capacitive effect of the player's hand in its region to create an audible tone changeable in pitch with hand movement to and from the detector. It is possible, by fluttering of the hand in space, to create a variable vibrato effect at the will of the player. Hence both the tone and its animation is determined solely by the spacing, and movement, of the hand from the proximity detector. This instrument is limited in the complexity of musical compositions capable of being rendered.
It would obviously be a great advantage if an electronic organ could be equipped with the same manual control of animation of created sound, but as both hands are usually fully occupied in the selection of the tones of the musical piece, it is not feasible to incorporate the hand operated facility of the "THEREMIN". Furthermore, the desired effect cannot be created by merely utilizing a proximity detector device in lieu of the present-day electro-mechanical arrangement of the organ's expression pedal. The inertia and balance of the pedal plate and its linkage is such that sufficiently swift and fluent control is not possible with the foot satisfactorily to obtain the above effects and many others such as selective attack and accent on notes.
A prime object of the invention is to provide an expression pedal for a musical instrument which is capable of improved control by the foot of the player than are contemporary pedals.
In accordance with one general form of the invention there is provided a foot-controlled expression pedal for a musical instrument comprising a supporting frame, an electrical proximity responsive device fixed with respect to said frame, and foot support means on said frame engageable beneath the heel of said foot for the latter's only support and permitting pivoting of said foot about said support means for freely raising and lowering the sole of said foot above said proximity responsive device to change the response thereof.
The invention will now be described in more detail with reference to the accompanying drawings in which: